First, the good news: the omni-competent Kay Scarpetta is back, along with her sidekicks, in a murder mystery that`s tighter than her last escapade, From Potter`s Field. Chief medical examiner for the state of Virginia and an FBI consultant, Kay finds ample opportunity to demonstrate her skills in the autopsy room and outside it, too: here, she also dives with a Navy SEAL rescue squad and, through her computer-genius niece Lucy, an FBI agent, takes an up-close-and-personal look at a robot operated via virtual reality. But there is bad news: the work lacks the extraordinary, can`t-go-to-bed-til-you`re-finished suspense of Cornwell`s earlier novels, e.g. Cruel and Unusual. The killers here, members of a nihilistic, fascist cult who think their founder akin to God, are identified early on but never developed as characters. Their crimes, while heinous, don`t baffle and tease the reader (or Kay) in the manner of the villain Temple Gault, who was dismissed in the last book. While Cornwell`s authoritative presentation of forensic sleuthing, FBI procedures and high-tech crime-fighting compensates mightily for the overneat dovetailing of characters` paths and even the implausible role Kay plays in the climax, the hurried, almost slapdash pace of the climactic scenes is disappointing from so accomplished a writer. But even at less than her best, Cornwell remains a master of the genre, instilling in readers an appetite that only she can satisfy. One million first printing; $750,000 ad/promo; Literary Guild, Mystery Guild and Doubleday Book Club main selections.